ABC of CPR: Airway Breathing Circulation

Cardiopulmonary Resuscitation (CPR) and Basic Life Support (BLS) are life-saving techniques used in emergencies when someone’s heart or breathing has stopped. For many years, the sequence was taught as A-B-C (Airway, Breathing, Circulation). However, since 2010, the American Heart Association (AHA) and other councils recommend starting with C-A-B (Compressions first, then Airway and Breathing). This change emphasizes the importance of keeping blood circulating as soon as possible.

This guide provides a clear overview of the C-A-B sequence of CPR, highlighting the correct techniques for each step:

  • Circulation (Compressions): Begin with chest compressions at a rate of 100–120 per minute and a depth of 5–6 cm in adults. Minimize interruptions.
  • Airway: After 30 compressions, open the victim’s airway with a head-tilt–chin-lift (or jaw thrust if spinal injury is suspected).
  • Breathing: Provide 2 rescue breaths if trained and able. If not, continue hands-only CPR with compressions only.

Circulation (C)

C is for Circulation/Compressions. In adult Basic Life Support, the priority is to start chest compressions immediately once cardiac arrest is suspected.

  • Check responsiveness & breathing: Tap and shout. If the victim is unresponsive and not breathing normally (only gasping), start CPR. Do not spend time on “look, listen, and feel.”
  • Chest Compressions: Place the heel of one hand on the center of the chest (lower half of the sternum), the other hand on top, and interlock fingers.
  • Proper Technique: Push hard and fast at a rate of 100–120 compressions per minute and a depth of 5–6 cm (2–2.4 inches) for adults. Allow full chest recoil after each compression.
  • Compression-to-Breath Ratio: For single rescuers, use 30 compressions to 2 breaths. If untrained or unwilling to give breaths, perform hands-only CPR.

Airway (A)

A is for Airway Management. After the first set of compressions, open the airway before giving rescue breaths.

  • Opening the Airway: Use the head-tilt–chin-lift. If spinal injury is suspected, use a jaw thrust if trained.

Breathing (B)

B is for Breathing. Rescue breaths deliver oxygen to the victim’s lungs when circulation is compromised.

  • Rescue Breathing: Give 2 breaths after 30 compressions if trained and able.
  • Proper Technique: Make a tight seal over the mouth (and nose for infants), deliver each breath over 1 second, and watch for chest rise. If the chest doesn’t rise, reposition the airway and try again.

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CAB in CPR

The "CAB" sequence in CPR replaced the traditional "ABC" approach in 2010 when the American Heart Association (AHA) updated its guidelines. The change was made to prioritize chest compressions and minimize delays in circulating oxygenated blood, which is critical during sudden cardiac arrest.

Here’s the breakdown of the CAB sequence:

  • C – Compressions: After confirming the victim is unresponsive and not breathing normally (or only gasping), begin chest compressions immediately. For adults, perform compressions at a rate of 100–120 per minute and a depth of 2–2.4 inches (5–6 cm).
  • A – Airway: Once compressions are underway, open the airway using the head-tilt, chin-lift method (or jaw thrust if spinal injury is suspected).
  • B – Breathing: Deliver 2 rescue breaths after every 30 compressions (30:2 ratio for single rescuer). Each breath should last about 1 second and make the chest rise.

The CAB sequence ensures blood flow starts as quickly as possible, increasing the victim’s chances of survival while still integrating airway and breathing support.

CAB sequence in CPR

When should CAB be used instead of ABC?

Since 2010, the CAB sequence has replaced the ABC sequence for all age groups—adults, children, and infants—in Basic Life Support (BLS). This change ensures that chest compressions are started without delay, improving the chances of survival during sudden cardiac arrest.

However, while CAB is universal, the importance of rescue breaths differs by situation:

  • Adults (sudden cardiac arrest): Compressions are the top priority. Hands-only CPR is acceptable if rescue breaths cannot be given.
  • Infants and children: Rescue breaths are critical because cardiac arrest often results from breathing problems, not heart rhythm issues.
  • Drowning, drug overdose, or asphyxial arrests: Early rescue breaths are essential to provide oxygen before compressions.

In every case, follow the CAB order, but adjust emphasis: start with compressions, then provide airway and breathing support as soon as possible. Always follow the latest AHA or local resuscitation council guidelines.

How Do ABC of CPR Protocols Differ in Infant CPR Compared to Adults?

In infant CPR compared to adult CPR, there are several key differences:

  1. Compression Technique: For infants, use two fingers to perform chest compressions, whereas for adults, you use the heel of your hand.
  2. Compression Depth: The depth of compression for infants is about 1.5 inches (4 cm), while for adults, it's about 2 inches (5 cm).
  3. Compression Rate: The compression rate for infants is the same as for adults, about 100 to 120 compressions per minute.
  4. Breathing: For infants, you cover both the infant's nose and mouth with your mouth and give gentle puffs of air, whereas for adults, you use mouth-to-mouth or mouth-to-mask ventilation.
  5. Head Positioning: In infants, the head is positioned in a neutral position, while for adults, it's tilted back slightly to open the airway.

How Does the ABC Assessment Impact the Use of an AED in Emergency Situations?

The ABC assessment is crucial in determining whether an Automated External Defibrillator (AED) should be used in an emergency situation. If a person is unresponsive, not breathing normally, and has no pulse, it indicates a cardiac arrest, and using an AED is recommended. The ABC assessment guides responders to prioritize actions in a systematic way, ensuring that life-saving interventions such as defibrillation are provided promptly.

How Do ABC of CPR Help in Managing a Choking Emergency?

In managing a choking emergency, the ABC of CPR (Airway, Breathing, Circulation) protocol plays a critical role:

  1. Airway: Check the airway to ensure it's not blocked. If the infant or adult can't breathe, perform a series of back blows and chest thrusts to dislodge the object obstructing the airway.
  2. Breathing: After attempting to clear the airway, assess whether the person is breathing. If they're not breathing or only making gasping sounds, begin CPR immediately.
  3. Circulation: If CPR is required, perform chest compressions following the appropriate technique for the age group until medical help arrives.

These steps aim to quickly and effectively clear the airway obstruction and restore normal breathing and circulation, thus preventing further complications or fatalities from choking emergencies.

Is ABC always the preferred method in CPR?

No, CAB is the preferred method, particularly for adults. This approach helps restore blood circulation quickly, which proves essential for sustaining organ function during a cardiac emergency.

How does CPR differ between adults and children?

CPR techniques differ significantly based on age, with children requiring less forceful compressions and adjusted ratios of breaths to compressions. These variations address the unique physiological characteristics and needs of younger patients.

Why is airway management critical in CPR?

Effective airway management ensures oxygen reaches the lungs and vital organs. Without a clear airway, even the best compressions will not adequately oxygenate the blood, severely limiting recovery potential.

How do BLS certification requirements cover ABC principles?

BLS training encompasses both CAB and ABC principles, equipping responders with essential skills for effective resuscitation. This comprehensive training prepares individuals to adjust their approach based on specific situations.

How can airway obstructions affect CPR outcomes?

Airway obstructions severely impact CPR effectiveness by preventing oxygen flow. Without air entering the lungs, high-quality chest compressions will not adequately restore oxygen levels in the blood.

What changes in the ABC sequence for unresponsive patients?

For unresponsive patients, the CAB approach is prioritized to quickly initiate chest compressions, vital for restarting blood circulation. This method proves essential in emergencies where rapid intervention saves lives.

What is the role of an EMS professional in ABC and CPR?

EMS professionals assess patient conditions, manage advanced airways, and deliver high-quality compressions. Their expertise proves vital in providing efficient CPR and maximizing recovery chances during emergencies.

Is the ABC of CPR always the preferred method for all age groups, or are there specific guidelines for different age groups?

No, the ABC of CPR is not always the preferred method for all age groups. The American Heart Association (AHA) updated its guidelines in 2010 to recommend the CAB sequence (Chest Compressions, Airway, Breathing) for adults to prioritize early chest compressions, which significantly improves survival rates. For infants and children, the traditional ABC sequence is still emphasized. This is because early rescue breaths are crucial for young children and infants, as they are more likely to suffer from respiratory causes of cardiac arrest. Studies show that initiating chest compressions within 1-2 minutes improves survival rates by up to 50% in adults, while timely rescue breaths are critical for pediatric cases.

Are there any specific variations in the ABC of CPR protocols for individuals with specific medical conditions or disabilities?

Yes, there are specific variations in CPR protocols for individuals with certain medical conditions or disabilities. For instance, patients with a tracheostomy require modified airway management techniques, such as providing breaths through the tracheostomy tube rather than the mouth. Individuals with severe obesity needs adjustments in compression technique due to a thicker chest wall, which affects compression depth. Research indicates that proper adaptations in these cases improves the effectiveness of CPR and outcomes. For example, using two hands or an alternative compression technique for obese patients ensures more effective chest compressions.

Are there limitations or challenges of using the ABC method in high-pressure environments?

Yes, limitations exist when using the ABC method in high-pressure environments. During large-scale emergencies, such as natural disasters, the focus often shifts to triage and managing multiple casualties, which disrupts the consistent application of the ABC method. Studies show that in such chaotic situations, maintaining the correct CPR sequence is challenging, potentially reducing the effectiveness of care provided. For example, research during mass casualty events has demonstrated that deviations from standard protocols are common, which impact patient outcomes.

How does the ABC approach integrate with advanced medical interventions during CPR?

The ABC approach integrates with advanced medical interventions by establishing a structured sequence for initial life-saving actions, which is complemented by more advanced procedures as they become available. This approach ensures that basic life-saving actions are taken promptly, which stabilizes the victim and enhances the effectiveness of subsequent advanced medical procedures. Studies indicate that effective initial CPR improves the success of advanced interventions and overall patient outcomes

Are there updated recommendations or changes to the ABC method based on recent research or guidelines?

Yes, recommendations for the ABC method have changed based on recent research. The AHA’s 2010 guidelines shifted from the ABC sequence to the CAB sequence for adults to highlight the critical importance of early chest compressions. This change is supported by research indicating that chest compressions alone improve survival rates in cardiac arrest victims by up to 40% when administered promptly. Ongoing research continues to refine CPR guidelines, emphasizing the need for evidence-based practices to enhance the effectiveness of resuscitation efforts.

What are the legal or certification implications of deviating from the ABC method during CPR?

Deviating from the ABC method during CPR generally does not lead to specific legal implications as long as the resuscitation provided meets established guidelines and is performed to the best of the rescuer’s ability. Certification programs from reputable organizations, including online providers like CPR Select, align with current guidelines and ensure that CPR training reflects the latest recommendations. Adhering to these guidelines is essential for maintaining certification and ensuring effective care. Certification programs emphasize following the recommended procedures, and deviations are typically assessed based on the context and adherence to best practices rather than resulting in legal liability.

CPR and Basic Life Support Training

The CPR training classes are readily available anytime, anywhere. There are no limitations for enrolling in CPR classes, including infant cpr classes, making the course open to everyone interested. Whenever life-threatening emergencies occur, waiting for the EMS to arrive might cost you the life of a loved one, especially in case of cardiac arrest.

CPR and Basic Life Support training are available online at an affordable cost and follow the latest guidelines of the American Heart Association. There are various advantages of taking basic cpr certification online over in-person training. If you choose an online BLS and CPR certification course, you acquire the same level of skills at a fair price at your convenience. While there are free CPR classes available, it's important that you get certified by reputable training center.

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Sources:

  • American Heart Association. (2015). 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation, 132(18_suppl_2), S444-S464.
  • Olasveengen, T. M., Mancini, M. E., & Perkins, G. D. (2018). Adult Basic Life Support and Cardiopulmonary Resuscitation Quality: A Review. Journal of the American College of Cardiology, 72(7), 827-835.
  • American Heart Association. (2016). 2015 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care: Pediatric Basic Life Support. Pediatrics, 137(5), e20154029.
  • O'Rourke, R. E., & Pancioli, A. M. (2019). Modified Cardiopulmonary Resuscitation Techniques for Patients with Tracheostomy or Severe Obesity. Prehospital Emergency Care, 23(4), 543-550.
  • Idris, I., & Becker, L. B. (2017). Evolution of CPR Guidelines: The Shift from ABC to CAB. Resuscitation, 116, 7-12.